var now = new Date();                    //当前日期      
var nowDayOfWeek = now.getDay();         //今天本周的第几天      
var nowDay = now.getDate();              //当前日      
var nowMonth = now.getMonth();           //当前月      
var nowYear = now.getYear();             //当前年      
nowYear += (nowYear < 2000) ? 1900 : 0;  //      
     
//格式化日期：yyyy-MM-dd      
function formatDate(date) {       
    var myyear = date.getFullYear();      
    var mymonth = date.getMonth()+1;      
    var myweekday = date.getDate();       
          
    if(mymonth < 10){      
        mymonth = "0" + mymonth;      
    }       
    if(myweekday < 10){      
        myweekday = "0" + myweekday;      
    }      
    return (myyear+"-"+mymonth + "-" + myweekday);       
}       
     
//获得某月的天数      
function getMonthDays(myMonth){      
    var monthStartDate = new Date(nowYear, myMonth, 1);       
    var monthEndDate = new Date(nowYear, myMonth + 1, 1);       
    var   days   =   (monthEndDate   -   monthStartDate)/(1000   *   60   *   60   *   24);       
    return   days;       
}      
     
//获得本季度的开始月份      
function getQuarterStartMonth(){      
    var quarterStartMonth = 0;      
    if(nowMonth<3){      
       quarterStartMonth = 0;      
    }      
    if(2<nowMonth && nowMonth<6){      
       quarterStartMonth = 3;      
    }      
    if(5<nowMonth && nowMonth<9){      
       quarterStartMonth = 6;      
    }      
    if(nowMonth>8){      
       quarterStartMonth = 9;      
    }      
    return quarterStartMonth;      
}      
//获得今天的日期
function getNowDayDate(){
    return formatDate(now);
} 
//获得本周的开始日期      
function getWeekStartDate() {       
    var weekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek);       
    return formatDate(weekStartDate);      
}       
     
//获得本周的结束日期      
function getWeekEndDate() {       
    var weekEndDate = new Date(nowYear, nowMonth, nowDay + (6 - nowDayOfWeek));       
    return formatDate(weekEndDate);      
}       
     
//获得本月的开始日期      
function getMonthStartDate(){      
    var monthStartDate = new Date(nowYear, nowMonth, 1);       
    return formatDate(monthStartDate);      
}      
     
//获得本月的结束日期      
function getMonthEndDate(){      
    var monthEndDate = new Date(nowYear, nowMonth, getMonthDays(nowMonth));       
    return formatDate(monthEndDate);      
}
      
//获得上月的开始日期      
function getLastMonthStartDate(){      
    var monthStartDate = new Date(nowYear, nowMonth-1, 1);       
    return formatDate(monthStartDate);      
}      
     
//获得上月的结束日期      
function getLastMonthEndDate(){      
    var monthEndDate = new Date(nowYear, nowMonth-1, getMonthDays(nowMonth)-1);       
    return formatDate(monthEndDate);      
}      
     
//获得本季度的开始日期      
function getQuarterStartDate(){      
          
    var quarterStartDate = new Date(nowYear, getQuarterStartMonth(), 1);       
    return formatDate(quarterStartDate);      
}      